About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Deformation Mechanisms, Microstructure Evolution, and Mechanical Properties of Nanoscale Materials
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Presentation Title |
Atomistic Modeling of Peierls Barriers to Dislocation Glide in Metals |
Author(s) |
Yipin Si, David L. McDowell, Ting Zhu |
On-Site Speaker (Planned) |
Yipin Si |
Abstract Scope |
Dislocation glide plays an important role in plastic deformation of crystalline solids. We perform nudged elastic band (NEB) calculations to determine the Peierls barrier and Peierls stress for screw and edge dislocations glide in face-centered cubic nickel. The minimum energy paths (MEPs) across multiple Peierls barriers are determined under different shear loads. The results demonstrate the decrease of Peierls barriers with increasing shear load and quantify the Peierls stresses. The calculated activation energies across sequential Peierls barriers are not constant from strain-controlled NEB. In contrast, the stress−controlled NEB method resolves this issue, giving the constant Peierls barriers even in small supercells. Furthermore, the free-end NEB methods are used to compute MEPs for long, highly tilted reaction paths. Our work demonstrates how to achieve accurate and efficient quantification of Peierls barriers to dislocation glide in metals, and provides a basis of investigation of Peierls barriers in compositionally complex alloys. |
Proceedings Inclusion? |
Planned: |